1. Field of the Invention
The invention relates to an arrangement for recording an information signal in a track on a record carrier, comprising
an input for receiving the information signal,
signal processing means for processing the information signal such that it can be recorded in the track,
count signal generating means for generating an array of subsequent different count signals and for supplying the different count signals to an output with a certain supply rate,
recording means, having at least one recording head, for recording the processed information signal in a track on the record carrier, and for recording the count signals in a track on the record carrier,
transport means for transporting the record carrier with a certain transport velocity in a longitudinal direction of the record carrier.
2. Description of the Related Art
Such an arrangement is known in the form of a helical scan videorecorder which is also capable of recording a VITC time code on the record carrier. The VITC code is described in the IEC standard publication no. 461 of 1986, see page 31 to 54. When a recording takes place in the known arrangement, the count signal generating means generates the count signals with incrementally increasing values, starting from a certain value which is preferably zero, with fixed increments. In this way, count signals are generated that are used as a time code, which count signals are recorded in the slant tracks on the record carrier. The time code recorded on the record carrier can be used for location purposes.
The known arrangement has the disadvantage that locating a certain position in the length direction of the record carrier sometimes fails.
It is an object of the invention to provide an arrangement for recording an information signal in a track on a record carrier, with which locating a certain position on the record carrier is possible with less ambiguity.
To that purpose, the arrangement according to the invention is characterized in that the count signal generating means are adapted to supply subsequent different count signals such that, independent of the value of the transport velocity during recording, a count signal is recorded in a substantially fixed location, viewed in the longitudinal direction of the record carrier, on said record carrier.
The invention is based on the following recognition. Generating the count signals with fixed increments and with a fixed supply rate, as is realized in the prior art arrangement, means that for all transport velocities of the record carrier during the recording of an information signal, the array of different count signals generated is the same as a function of time. Suppose that the information signal can be recorded in a short play or a long play mode of the arrangement. In the long play mode, the record carrier transport velocity has a certain nominal value. In the short play mode, the record carrier transport velocity is higher, say twice the nominal velocity. Identical count signals will not be recorded in the same location for both velocities. In fact, the count signals recorded in the short play mode will substantially coincide with the even or the uneven count signals only of the array of count signals when recorded in the long play mode. This means that the count signals recorded are not location-related.
A further disadvantage is that, when overwriting a signal recorded earlier in the long play mode, by a signal in the short play mode, the sequence of count signals at the end of the insert is not continuous anymore with the sequence of count signals in the original recording following the insert. Further, the possibility arise that identical count signals can occur in the insert and the original recording following the insert. This makes the localization of a position on the record carrier intricate.
In accordance with the invention, count signals are recorded that have a direct relationship to a corresponding position on the record carrier where they are recorded. This means that, independent of the transport velocity of the record carrier during recording, the same count signal will be recorded on a specific location on the record carrier. This makes it possible to address a location on the record carrier in an unambiguous and unique way. This makes it possible to determine, in every position on the tape, how far (in meters) the begin position and the end position of the tape are away from the present location. Moreover, this makes it possible to determine the xe2x80x98time-usedxe2x80x99 and the xe2x80x98time-leftxe2x80x99 for the present location, for any mode (such as: short play, long play or super long play) in which the arrangement can be used.
In order to realize this, the arrangement may be characterized in that, to that purpose, the count signal generating means are further adapted to supply such count signals, that the difference between subsequent count signals in the array of different count signals is substantially proportional to the transport velocity of the record carrier during recording. This results in lesser count signals being recorded on the record carrier in the case of higher transport velocities, the increment value between two successive different count signals being larger. This embodiment is of special use in the case that a recording of the information signal in slant tracks on a record carrier is carried out.
Another possibility is that the arrangement is characterized in that, to that purpose, the count signal generating means are further adapted to supply the subsequent different count signals with a supply rate which is substantially proportional to the transport velocity of the record carrier during recording. In this case, the increment value can be kept constant for the various transport velocities, and the same array of count signals is recorded on the record carrier, independent of the transport velocity during recording.
In a situation in which a first information signal has been recorded in a first portion on the record carrier, the arrangement be further characterized in that, for recording a second information signal directly after the first information signal in a second portion on the record carrier, the arrangement is adapted to read the count signal lastly recorded in the first portion on the record carrier, to supply the count signal lastly recorded to the count signal generating means, that for recording the second information signal, the count signal generating means are adapted to generate count signals starting from the count signal lastly recorded in the first portion. This has the advantage that the sequence of count signals recorded on the record carrier will be continuous over the boundary between the first portion and the beginning of the second portion of the record carrier. Moreover, in the case that the second information signal is an insert to be recorded over an original recording, this results in a continuous sequence of count signals over the boundary separating the end of the insert and the part of the original recording following the insert.
An arrangement for recording a first information signal in the form of a video signal based on 25 pictures per second and for recording a second information signal based on 30 pictures per second may be characterized in that the arrangement is adapted to receive a first information signal in the form of a videosignal based on 25 pictures per second or a second information signal in the form of a videosignal based on 30 pictures per second and to record said first or second information signal in slant tracks on the record carrier, the arrangement further comprising clock extracting means for extracting a clock signal from the first or second information signal applied to the input and for supplying the clock signal to an output, the clock signal being substantially proportional to the number of pictures per second in the first or second information signal, the output of the clock extraction means being coupled to a clock signal input of the count signal generating means, the count signal generating means being adapted to supply subsequent different count signals in response to the clock signal received, with a supply rate which is substantially proportional to the frequency of the clock signal, and with such difference between subsequent different count signals that the following relation is met, independent of the first or the second information signal being recorded on the record carrier, and with the transport velocity of the record carrier during recording of said first or second information signal being the same:
Fsxc3x97D=constant, 
where Fs is the supply rate and D is the difference between subsequent different count signals.
This has the advantage that also for recording different kind of information signals in the form of video signals which are based on 25 or 30 pictures per second, count signals are recorded which are location related.